
uniform vec4 color;
uniform float speed;
vec2 center = vec2(0.5,0.5);
czm_material czm_getMaterial(czm_materialInput materialInput){
  czm_material material = czm_getDefaultMaterial(materialInput);
  vec2 v_st = materialInput.st; // 获取uv坐标
  float invAr = 1.0; 
  float iTime = czm_frameNumber * speed / 100.0;
  // vec2 p = (2.0*fragCoord.xy-iResolution.xy)/iResolution.y;
  float x = (center.x-v_st.x);
  float y = (center.y-v_st.y) *invAr;

  vec2 uv = vec2(x , y);
  // vec3(0.84, 0.7, 0.4)
  float r = length(uv) * 4.4;

  float a = pow(r, 2.0);
  float b = sin(r * .08 - .6);
  float c = sin(r - 0.010);
  float s = sin(a - iTime * .2 + b) * c;

  float d = abs(1.0 / (s * 30.8)) - 0.001;
  material.alpha = pow(d, 1.) * color.a;
  material.diffuse = color.rgb * d;
  return material;
}